Eudonia mercurella
Wingspan 16-19 mm. Its similarity to several other species makes it difficult to identify.
Scopariinae are a difficult group to identify and sometimes it is necessary to refer to genitalia to be sure. A useful guide can be found at the following LINK

Woodland, parks and gardens.
The adults, which are easily attracted to light, fly at night from June to September but can be disturbed from their daytime resting places of tree trunks and rocks etc.
The larvae, like many of its congeners, feed on mosses growing on tree trunks and walls.
A common species in most of Britain. In the Butterfly Conservation’s Microlepidoptera Report 2011 this species was classified as common.
Quite common in Leicestershire and Rutland. L&R Moth Group status = A (common and resident)
Leicestershire & Rutland Map
Enter a town or village to see local records
MAP KEY:
Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015